Priso prints are printed one color layer at a time. Since we add one color at a time, this can cause slight differences in registration, which is what makes each print unique! There might also be something called roller-track transfers from the ink. We try to mitigate this as much as possible by printing from light to dark, but roller transfer and slight misalignment still naturally occur in this process. I quality-check to the best of my ability. It's all a part of the Risograph process. When all is said and done, you get this amazing one-of-a-kind print.